The present invention relates to a device for cleaning pipes, in particular, sewage pipes from household- or industry waste water.
Incrustations, depositions, biofilm and formations at pipe walls in pipe systems represent a considerable problem in connection with sewage pipes, water treatment plants, in ground water remediation, and in industrial installations. Construction damage through road works can lead to blockages in underground sewage systems due to, such as, for example, concrete that has penetrated through cracks or ingrown tree roots. Torrential rain can render sewer lines blocked by leaves, refuse and similar material. Industrial, domestic and mining waste water normally contain a great array of nutrients that are microbially useful and that thus leads to a disproportionally strong growth of biofilm at the walls of the pipes up to complete blockages. The cleaning capacity of water treatment plants is thus hampered and the quality of the treated waste water reduced while interrupting operation for costly cleaning work is necessary.
Drainage units and dewatering of tunnel systems and streets particularly in hillside locations are likewise affected by this. A stoppage to conduct maintenance and remediation can already represent a hardship for the local economy.
When penetration of foreign objects or pipe blockages occur, usually the pipes are either entirely impaired or are only partially usable. Pipes that are completely blocked can be unblocked with only considerable and costly effort or sometimes cannot be totally freed from these foreign objects, as for example under streets, houses, transformer stations, walls and other such structures.
Conventional cleaning methods such as mechanical cleaning or customary rinsing techniques are borderline effective. Mechanical cleaning has the added danger of damaging the pipes. This refers also to the flushing technique that utilizes spin chains in addition to flushing jets. The flushing technique results sometimes only in an inadequate cleaning when the encrustations are very resistant, or the depositions at the pipe wall are biofilms. The high turn around time in the prescribed maintenance intervals leads to economic loss for the operators of the pipe systems because of long cleaning cycles.
Various devices and methods are known for eliminating such problematic sites. Basically, there are a variety of mechanical, chemical and hydrodynamic pipe cleaning devices and/or methods available.
When applying mechanical pipe cleaning, flexible spirals are manually inserted into the pipe that are mostly put into rotation by an electric drive. Thus, solid depositions are eliminated from the inner pipe walls. These devices are very common, however their limitation shows when the encrustations are tougher than the pipe wall itself. This is particularly so with pipes from plastic that have, during their lifetime, become brittle due to evaporation of softener in the plastic. The stress through repeated striking when applying mechanical pipe cleaning systems can lead to pipe breakage.
When applying chemical pipe cleaning, the intention is to dissolve the encrustation. For this purpose, special cleaning liquids, mostly acids of a certain concentration are introduced into the pipe. The success of that type of cleaning is however quite uncertain, as the chemical reactions in the pipe to be cleaned happen in a rather uncontrolled manner. Under certain circumstances, this cleaning process has to be repeated multiple times until the desired cleaning effect has been realized. A disadvantage is thereby the considerable burden on the environment due to the chemicals utilized.
The hydrodynamic pipe cleaning has been established especially for sewer cleaning. Thereby, a rinsing head is inserted into the pipe to be cleaned and a pressurized cleaning liquid introduced via a rinsing hose connected to the rinsing head. In this manner, the cleaning liquid not only serves the cleaning of the walls but also generates a forward motion of the rinsing head due to the principle of recoil force. For this purpose, the rinsing head is provided with several rearward oriented bores such that emission of the high pressure liquid sprays on the one hand cleans soilage from the pipe inner walls and on the other hand the rinsing head generates the forward motion. Thus, the rinsing head must only be inserted into the starting opening of the pipe from where it then moves through the pipe system on its own. Those systems require the majority of the working liquid for the forward feed, whereby the working liquid reaches the pipe with great speed in opposite direction to the rinsing head.
For the removal of tough encrustations, such as for example lime scale and urine scale build-up, a high pressure spray, that is, pressures of up to several hundred bar is required. While rinsing heads with pressures of up to 200 bar and flow-through amounts of several hundred 100 l/per minute up to 1400 l/per minute are also in operation, the energy emitted from the nozzles are only partially converted into cleaning capacity. The greater portion serves the forward motion of the rinsing head and the transport of loose material such as for example loose stones, gravel and sand that are carried off by the rinsing water stream.
With the maximum pressure water-jet robotics, a rotating liquid jet under high pressure and high velocity is directed toward the material to be removed whereby, the majority of kinetic energy is used to eliminate the faulty site. Maximum pressure water-jet robotics is derived from the method of water jet cutting. In water jet cutting, the material to be treated is subjected to maximum pressure water jet for separation. This jet carries a pressure of up to 6000 bar and reaches exit velocities up to 1000 m/s. The maximum pressure water jet allows treatment of almost all materials from foamed material up to cutting a sapphire. The maximum pressure water jet has much application in the plastics field, in the fields of metal treatment, leather- and stone treatment. By pivoting a cutting head with a cutting vector drive, as in a 3D cutting, any number of complex shapes can be cut in spatial dimension.
DE 20 2014 000 026 U1 describes a device for the treatment of pipe walls of closed sewer systems by means of maximum pressure liquid jet with a nozzle body having at least one jet nozzle. The jet nozzle is disposed at the front end of the device and serves the creation of a forwardly directed focused jet of a liquid medium. The forward motion of the jet includes that the jet direction matches the axis of the sewer pipe and also that the direction of the jet, or the jets, have an angle of −90°<α<90° relative to the sewer pipe axis depending on the type and degree of the depositions and obstructions. To that end, a focused jet is a jet that is created by means of a nozzle opening with a much reduced diameter, locally applied with high force to the material to be removed. To remove large scale material, a greater number of nozzles are utilized and/or the nozzle or the jet is moved to scan across the respective surface. A scanning is for example realized through a rotation nozzle, where the nozzle body itself rotates or, in the area of the jet exit from the nozzle body, for example, a finger-shaped insert rotates in the hollow space in front to the output such that the emerging jet circles resulting in a conical jet formation. The device includes a movable carriage for moving and positioning of the nozzle body in the sewer canal in addition to a medium supply to supply the nozzle jet with a medium under high pressure. The carriage and the nozzle body are constructed so that both can be positioned, at least along the entire length of their bottom side, at a distance to the walls of the sewer canal. A pneumatic or hydraulic activated fixing pad is arranged at the rear of the carriage and configured in such a way that in an actuated state the position of the carriage can be fixed in the canal by pressing the fixing pad but without closing off the canal.
The maximum pressure water jet robotics is a very recent method utilized in pipe cleaning. Working pressure is usually 1000 to 2500 bar. Currently on the market for the maximum pressure water jet robotics is the system by Mauerspecht GmbH. The Drain-Jet Robotics® is designed for pipe cross sections of from DN 180 with which a controlled and camera-supported removal of residue can be realized. This is accomplished in substantially shorter time as compared to using the conventional grinding robots or hydrodynamic pipe cleaning systems. The cutting of inliners, the removal of calcium- and concrete depositions as well as the cutting of steel foreign bodies can be realized at a very high level. This system is however limited in its application since it can be utilized with straight pipes only and for sleeve misalignments only from DN 250.
From DE 10 2009 007 946 A1, a device is known for hydrodynamic cleaning of inner pipe walls, in particular water carrying pipes in the domestic area which includes a high pressure cleaning nozzle with a high pressure cleaning hose attached thereto for supplying pressurized cleaning liquid, especially water. The cleaning device further includes a flexible, pressure stable bar or rod-shaped sliding device, with a high pressure cleaning nozzle is disposed at one end and suitable for insertion into the pipe to be cleaned. The cleaning device comprises in addition a pipe suitable carriage on which the high pressure cleaning nozzle and/or a portion of the high pressure hose extension is fastened. The cleaning work can be monitored with a camera connected to a video data line that is disposed in proximity of the high pressure cleaning nozzle. Thereby, the high pressure cleaning nozzle is moved by means of the bar- or rod shaped moving device to the location to be cleaned. This system operates normally with a pressure of 100 bar to maximal 500 bar.
As a further system, steerable satellite rinsing cameras are available on the market. These systems exploit the low pressure water jet directed rearward toward the pipe wall in order to move along the pipe. An additional utility, a certain cleaning effect of the rearward pipe is realized. In order to examine the condition and thus determine the correct functional condition or check leakage of the pipe, a further camera navigates the process to be carried out. Solid depositions, protruding obstacles cannot be eliminated with such a system.
DE 20 2010 016 857 U1 describes a high pressure water jet device which includes a flat bed driver carriage moving on four wheels with a nozzle bracket mounted at the front end. The nozzle bracket holds a nozzle with several nozzle openings in radial orientation relative to the canal and vertical to the drive direction. The nozzle bracket includes a pivot arm mounted at the front end of the carriage. By means of the pivot arm the nozzle is, for example, movable in two drive directions; perpendicular as well as parallel to each other. In addition, the nozzle is pivotable around its horizontal, parallel to the driving direction oriented swivel axis, which, for example, may be the axis of the nozzle pivotable around 360°. If a firm connection of the nozzle to the medium supply has been established, the nozzle swivels alternating around the 360°. Additionally, a camera is provided which is suitable to detect the environment of the canal, for example any branching in the canal or any obstacles, so that corresponding to the situation, an operator outside the canal can react to preprogrammed alerts of the device. A camera can also capture an image of the controls and transmit the photo images to the outside operator.
DE 20 2011 000 650 U1 describes a device for the examination and cleaning of pipes and pipe lines, in particular sewer lines that include a cleaning head additionally provided with a camera and wherein each of these are disposed at the end of the high pressure hose. The cleaning head is provided with one or more circumferentially disposed nozzles that are optionally configured for controlling and switching actions. The nozzles can move the cleaning head precisely in one direction and can direct it simply into an arm of the canal. To control the position, the camera images are consulted. The nozzle or nozzles at the circumference are configured rotatable and can be operated by a motor. The rotatable nozzle can always be pivoted in precise manner in the opposite direction in which the cleaning head is being moved. According to a variant, it is also possible to dispose the circumferential nozzle at the center axis so that it can revolve around this center axis.
Also offered on the market are canal milling robots by various producers that are utilized for operation on canal rehabilitation. The robot is for that purpose provided with a milling motor that can be driven by hydraulic or pneumatic means. Especially constructed milling tools are utilized for the deposited materials to be removed. The milling tool allow only a point removal of the material deposition. Manual control and the characteristics of the milling tools render any removal of deposition without contacting the canal wall and thus non-damaging not feasible or feasible only through excessive use of time.
A further commonly-used method is the removal of obstacles in the older pipes by means of spin ropes and spin chains. Spin chains are usually used in removal of solid depositions such as calcium, cement slurry, roots and such. Thereby, the driving nozzle rotates with the same speed as the chains to realize a precisely defined grinding effect within the pipe. While the chains should always correspond to the pipe size, the inner wall surface of the pipe is always being affected and camera monitoring cannot permanently cover the entire work process. A final check is carried out at the end of the process by means of a separately conducted camera check. If the cleaning result was not satisfactory, the process has to be repeated.